PerfectOn {010} perfect; on {100} good but interrupted; on {101} poor; on {001}, in traces.

Fracture:

Irregular/Uneven

Density:

2.77 - 2.85 g/cm3 (Measured) 2.805 g/cm3 (Calculated)

Crystallography of Beryllonite

Crystal System:

Monoclinic

Class (H-M):

2/m - Prismatic

Space Group:

P21/b

Space Group Setting:

P21/c

Cell Parameters:

a = 8.178(3) Å, b = 7.818(3) Å, c = 14.114(6) Åβ = 90°

Ratio:

a:b:c = 1.046 : 1 : 1.805

Unit Cell Volume:

V 902.39 Å³ (Calculated from Unit Cell)

Z:

12

Morphology:

Crystals tabular {010} to short prismatic [010]. Crystals are frequently very complex, especially in the zones [100] and [010]. Faces in the zone [010] near {100} may be united in oscillatory combination. Crystal faces often dull or roughened, or, in some cases, delicately etched. Crystals frequently exhibit a columnar structure due to the presence of hollow canals and fluid cavities arranged parallel to [010].

Twinning:

On plane {101}, as both contact and penetration twins; repeated at times, or in pseudo-hexagonal stellate forms; also polysynthetic {110} and {100}.

Localities for Beryllonite

map shows a selection of localities that have latitude and longitude coordinates recorded. Click on the symbol to view information about a locality.
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(TL) indicates type locality for a valid mineral species. (FRL) indicates first recorded locality for everything else. ? indicates mineral may be doubtful at this locality. All other localities listed without reference should be considered as uncertain and unproven until references can be found.